feat: Add new sidebar for Chatwoot V4 (#10291)

This PR has the initial version of the new sidebar targeted for the next major redesign of the app. This PR includes the following changes

- Components in the `layouts-next` and `base-next` directories in `dashboard/components`
- Two generic components `Avatar` and `Icon`
- `SidebarGroup` component to manage expandable sidebar groups with nested navigation items. This includes handling active states, transitions, and permissions.
- `SidebarGroupHeader` component to display the header of each navigation group with optional icons and active state indication.
- `SidebarGroupLeaf` component for individual navigation items within a group, supporting icons and active state.
- `SidebarGroupSeparator` component to visually separate nested navigation items. (They look a lot like header)
- `SidebarGroupEmptyLeaf` component to render empty state of any navigation groups.

----

Co-authored-by: Pranav <pranav@chatwoot.com>
Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/dashboard/components-next/sidebar/SidebarGroupSeparator.vue

@@ -0,0 +1,25 @@
+<script setup>
+import Icon from 'next/icon/Icon.vue';
+
+defineProps({
+  label: {
+    type: String,
+    default: '',
+  },
+  icon: {
+    type: String,
+    default: '',
+  },
+});
+</script>
+
+<template>
+  <div
+    class="flex items-center gap-2 px-2 py-1.5 rounded-lg h-8 text-n-slate-10 select-none pointer-events-none"
+  >
+    <Icon v-if="icon" :icon="icon" class="size-4" />
+    <span class="text-sm font-medium leading-5 flex-grow">
+      {{ label }}
+    </span>
+  </div>
+</template>